Pirelli Motorsport director Paul Hembery says the F1 tyre supplier would prefer to use a more modern car for its testing programme.

This season, the team has been making use of a Renault R30 as used by Robert Kubica and Vitaly Petrov in 2010, with the car having replaced the Toyota chassis that was used last year.

It has meant however that the supplier is using a car that is built to different regulations than those in place this season and Hembery said the fact that the Renault is two years old meant it was getting different results in testing to what teams were experiencing on race weekends.

"The same tyres behave very different when using a car from 2010," he was quoted as telling Total Race. "The aerodynamic balance of the car is very different and that acts on the tyres. This year the teams have suffered problems, especially with the front tyres, but there has also been overheating with the rears.

"We did not encounter these problems when testing because the car is two years old - but that is the only car we can use. It was a huge challenge to get hold of that car. I would obviously prefer one of the current test cars, but that is not going to happen.

"Teams need about 18 months to fully develop a car, so even using one from last year is not possible. Developing the different compounds needs to be very precise and it is very difficult to get everything right when we are not testing with a suitable car."